Thirty Days Has September

 7 -8    8   8  -8 -8 7
Thirty days has September

8 -9    9    9  -9 -9 8
April, June and November.

7    7   7    7    6 -7   7
All the rest have thirty-one,

7  7   6 6 6 6  6 7
Saving February alone,

  9   -9   8 -8   7      -7 -6  -7
Which has twenty-eight, rain or shine.

 6   6   6    9     9  9   7
And on leap years, twenty-nine.

This can be played in the  4 - 8 range
with good results.  Some problems on
the -6 equivalent in the lower octave.